Ticker · CUSIP 457730109

INSP

INSPIRE MED SYS INC

Healthcare·Medical Devices

···Share

Holders (tracked)

Combined shares

5,759,961

Combined value

$531.24M

Last close

$57.59

Quarter

2025Q4

Price is -37.6% vs the avg quarter-end implied price across tracked holders.

Price · 1Y$57.59-92.62 (-61.66%)H $161.88 · L $50.13 · Avg Vol 1.1M

Tracked holders · last 8 quarters

+6 vs previous quarter over the last 8.

SEC event timeline

25 events

Paul Tudor Jones (Tudor Investment) opened position2026-02-17
+112,873 shares · 2025Q4
Position
Ken Griffin (Citadel Advisors) trimmed2026-02-17
−1,237,091 shares · 2025Q4
Position
AQR Capital Management trimmed2026-02-17
−22,377 shares · 2025Q4
Position
Ron Baron (Baron Capital / BAMCO) added2026-02-17
+147,463 shares · 2025Q4
Position
Two Sigma Investments added2026-02-17
+22,363 shares · 2025Q4
Position
D.E. Shaw & Co. added2026-02-17
+853,305 shares · 2025Q4
Position
Izzy Englander (Millennium Mgmt) trimmed2026-02-17
−154,668 shares · 2025Q4
Position
Steve Cohen (Point72) exited2026-02-17
−91,896 shares · 2025Q4
Position
T. Rowe Price added2026-02-17
+283,243 shares · 2025Q4
Position
Wellington Management opened position2026-02-17
+2,211,091 shares · 2025Q4
Position
Ray Dalio (Bridgewater Associates) trimmed2026-02-13
−17,225 shares · 2025Q4
Position
Renaissance Technologies added2026-02-12
+255,768 shares · 2025Q4
Position
Norges Bank (Norway SWF) opened position2026-02-10
+129,570 shares · 2025Q4
Position
Baillie Gifford & Co exited2026-01-23
−1,084,350 shares · 2025Q4
Position
Two Sigma Investments added2025-11-14
+17,802 shares · 2025Q3
Position
D.E. Shaw & Co. added2025-11-14
+344,635 shares · 2025Q3
Position
AQR Capital Management trimmed2025-11-14
−71,993 shares · 2025Q3
Position
Izzy Englander (Millennium Mgmt) opened position2025-11-14
+356,808 shares · 2025Q3
Position
Steve Cohen (Point72) added2025-11-14
+16,491 shares · 2025Q3
Position
T. Rowe Price trimmed2025-11-14
−38,710 shares · 2025Q3
Position
Ron Baron (Baron Capital / BAMCO) trimmed2025-11-14
−301,729 shares · 2025Q3
Position
Renaissance Technologies added2025-11-13
+28,200 shares · 2025Q3
Position
Norges Bank (Norway SWF) exited2025-11-13
−239,390 shares · 2025Q3
Position
Ray Dalio (Bridgewater Associates) trimmed2025-11-13
−52,695 shares · 2025Q3
Position
Baillie Gifford & Co trimmed2025-10-31
−29,538 shares · 2025Q3
Position

Insider activity

Last 30 days

Net (open-market)

Buys

0 · $0

Sells

0 · $0

Unique insiders

Date	Insider	Code	Shares	Price	Value
04-15	Ellis Gary Lee Director	A	518	$52.07	$27.0K
04-15	Broader Shelley G Director	A	342	$52.07	$17.8K
04-15	Melenikiotou Georgia Director	A	307	$52.07	$16.0K
04-15	Tansey Casey M Director	A	308	$52.07	$16.0K

View full insider history for INSP →

Follow-the-investor returns

If you'd copied each holder of INSP…

Cost basis inferred from each manager's quarter-over-quarter position changes. Sorted by % return on the position they're still holding.

Investor	First in	Cost basis	Return	Position value today
Izzy Englander (Millennium Mgmt)	2018Q2	$77.95	-26.1%	$5.8M
Izzy Englander (Millennium Mgmt)	2018Q2	$77.95	-26.1%	$5.8M
D.E. Shaw & Co.	2018Q3	$88.07	-34.6%	$69.8M
Ken Griffin (Citadel Advisors)	2019Q1	$91.70	-37.2%	$29.4M
Ken Griffin (Citadel Advisors)	2019Q1	$91.70	-37.2%	$29.4M
Ken Griffin (Citadel Advisors)	2019Q1	$91.70	-37.2%	$29.4M
Paul Tudor Jones (Tudor Investment)	2018Q4	$93.50	-38.4%	$179K
Paul Tudor Jones (Tudor Investment)	2018Q4	$93.50	-38.4%	$179K
Paul Tudor Jones (Tudor Investment)	2018Q4	$93.50	-38.4%	$179K
T. Rowe Price	2018Q4	$100.88	-42.9%	$17.7M
Ron Baron (Baron Capital / BAMCO)	2019Q1	$102.77	-44.0%	$19.4M
Wellington Management	2018Q2	$103.87	-44.6%	$127.3M
Two Sigma Investments	2018Q2	$107.65	-46.5%	$3.4M
Renaissance Technologies	2019Q2	$124.61	-53.8%	$23.7M
Ray Dalio (Bridgewater Associates)	2021Q1	$146.12	-60.6%	$4.1M
AQR Capital Management	2019Q2	$184.25	-68.7%	$1.6M
Steve Cohen (Point72)	2019Q1	$186.68	-69.1%	$242K
Steve Cohen (Point72)	2019Q1	$186.68	-69.1%	$242K
Norges Bank (Norway SWF)	2019Q2	$3374.21	-98.3%	$7.5M

Who moved on this name in 2025Q4

Position changes reported for the latest quarter, grouped by direction.

New positions3

Wellington Management
+2,211,091
$203.9M
Norges Bank (Norway SWF)
+129,570
$12.0M
Paul Tudor Jones (Tudor Investment)
+112,873
$10.4M

Added to5

D.E. Shaw & Co.
+853,305
$78.7M
Renaissance Technologies
+255,768
$23.6M
Ron Baron (Baron Capital / BAMCO)
+147,463
$13.6M
Two Sigma Investments
+22,363
$2.1M
T. Rowe Price
+283,243
$26K

Trimmed4

Ken Griffin (Citadel Advisors)
−1,237,091
$114.1M
Izzy Englander (Millennium Mgmt)
−154,668
$14.3M
AQR Capital Management
−22,377
$2.1M
Ray Dalio (Bridgewater Associates)
−17,225
$1.6M

Exited2

Baillie Gifford & Co
−1,084,350
$80.5M
Steve Cohen (Point72)
−91,896
$6.8M

Institutional ownership over time

Distinct super-investors holding this ticker · combined dollar value, by quarter.

Quarter	Holders	Shares	Combined value	Δ holders
2022Q1	19	4,327,509	$44.71B	—
2022Q2	17	4,557,551	$36.04B	-2
2022Q3	22	5,385,588	$955.2M	+5
2022Q4	20	5,774,612	$1.45B	-2
2023Q1	22	5,252,393	$1.23B	+2
2023Q2	23	4,920,471	$1.60B	+1
2023Q3	21	4,758,947	$944.4M	-2
2023Q4	18	4,802,186	$976.9M	-3
2024Q1	17	7,228,948	$1.55B	-1
2024Q2	21	7,083,103	$947.9M	+4
2024Q3	20	4,971,589	$1.05B	-1
2024Q4	18	2,631,469	$487.8M	-2
2025Q1	17	2,734,046	$434.0M	-1
2025Q2	16	2,494,077	$323.7M	-1
2025Q3	13	4,294,992	$318.7M	-3
2025Q4	19	5,759,961	$531.2M	+6

Who owns INSP

19 super-investors · 2025Q4

Tracked stake

5.76M

Combined value

$531M

% of shares outstanding

—

shares-out unknown

Quarter action mix

New5Added5Trim7Sold2

#	Manager	Shares	Value	% of book	Last action
1	Wellington Management	2.21M	$204M	0.0%	New+2.21M
2	D.E. Shaw & Co.	1.21M	$112M	0.1%	Added+853.3K
3	Ken Griffin Citadel Advisors	511.3K	$47M	0.0%	Trim−1.24M
4	Renaissance Technologies	410.8K	$38M	0.1%	Added+255.8K
5	Ron Baron Baron Capital / BAMCO	337.5K	$31M	0.1%	Added+147.5K
6	T. Rowe Price	308.2K	$28M	0.0%	Added+283.2K
7	Izzy Englander Millennium Mgmt	202.1K	$19M	0.0%	Trim−154.7K
8	Norges Bank Norway SWF	129.6K	$12M	0.0%	New+129.6K
9	Paul Tudor Jones Tudor Investment	112.9K	$10M	0.0%	New+112.9K
10	Izzy Englander Millennium Mgmt	100.2K	$9M	0.0%	Trim−154.7K
11	Ray Dalio Bridgewater Associates	71.7K	$7M	0.0%	Trim−17.2K
12	Two Sigma Investments	59.5K	$5M	0.0%	Added+22.4K
13	Ken Griffin Citadel Advisors	35.3K	$3M	0.0%	Trim−1.24M
14	AQR Capital Management	27.0K	$2M	0.0%	Trim−22.4K
15	Ken Griffin Citadel Advisors	15.8K	$1M	0.0%	Trim−1.24M
16	Steve Cohen Point72	4.4K	$406K	0.0%	Sold−91.9K
17	Steve Cohen Point72	4.2K	$387K	0.0%	Sold−91.9K
18	Paul Tudor Jones Tudor Investment	3.1K	$286K	0.0%	New+112.9K
19	Paul Tudor Jones Tudor Investment	3.1K	$286K	0.0%	New+112.9K

Recent moves

20 transactions

NEWPaul Tudor Jones (Tudor Investment)
+112,873 · 2025Q4
ADDD.E. Shaw & Co.
+853,305 · 2025Q4
TRIMAQR Capital Management
−22,377 · 2025Q4
TRIMKen Griffin (Citadel Advisors)
−1,237,091 · 2025Q4
ADDRon Baron (Baron Capital / BAMCO)
+147,463 · 2025Q4
TRIMIzzy Englander (Millennium Mgmt)
−154,668 · 2025Q4
SOLDSteve Cohen (Point72)
−91,896 · 2025Q4
ADDT. Rowe Price
+283,243 · 2025Q4
ADDTwo Sigma Investments
+22,363 · 2025Q4
NEWWellington Management
+2,211,091 · 2025Q4
TRIMRay Dalio (Bridgewater Associates)
−17,225 · 2025Q4
ADDRenaissance Technologies
+255,768 · 2025Q4
NEWNorges Bank (Norway SWF)
+129,570 · 2025Q4
SOLDBaillie Gifford & Co
−1,084,350 · 2025Q4
NEWIzzy Englander (Millennium Mgmt)
+356,808 · 2025Q3
ADDSteve Cohen (Point72)
+16,491 · 2025Q3
ADDTwo Sigma Investments
+17,802 · 2025Q3
ADDD.E. Shaw & Co.
+344,635 · 2025Q3
TRIMT. Rowe Price
−38,710 · 2025Q3
TRIMRon Baron (Baron Capital / BAMCO)
−301,729 · 2025Q3

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